A collision avoidance system for a vehicle is required to accurately detect targets such as other vehicles, pedestrians, etc. From this viewpoint, there is a technology that uses both a radar apparatus and a camera for detecting targets.
For example, the technology described in Japanese Patent Application Publication No. 2014-122873, which will be referred to as PTL, determines whether an object detected based on an image captured by a camera (hereinafter referred to as a camera object) and an object detected by a radar apparatus (hereinafter referred to as a radar object) are the same as each other.
Specifically, this technology sets a radar-object region that contains a detected point of a radar object and a margin around the detected point; the margin is based on detection errors. The technology also sets a camera-object region that contains a detected point of a camera object and a margin around the detected point; the margin is based on detection errors. The technology determines that the radar object and the camera object are identical to each other if the radar-object region and the camera-object region mutually overlap with each other.